Today, I walked down the street to my local independent bookstore, spied a title I'd been meaning to buy in the window, whipped out my phone, scanned the cover, and within seconds, I'd placed an order. I saved $7. It'll be on my desk by Friday. It was easy, it was seamless, it wasn't a fair fight. That's Amazon Flow.

Amazon's iOS app is getting an aggressive overhaul that might turn you into the kind of jerk that shops for groceries and books on your phone, even if you've resisted such futuristic laziness forever.

The Amazon app is already a breeze to use: It's the best and fastest way to buy something when you're nowhere near a computer, which is inevitably when you remember that you really need to buy something. How did we ever get by without ordering some thumbtacks, pens, and diapers all while sloshed at the bar. Amazon's app has always been great at that.

But with the new "Flow" tool on Amazon's iOS app, you'll be looking up items by simply pointing your phone at them. The app has had visual search since since 2009, but this new version is way slicker than the existing "Scan it" and "Snap it" search features that already exit. Until now, you could scan the barcode of an item you'd like to buy or snap a picture of it and search it against Amazon's image database—provided it's a book, DVD, CD, or video game. Scan it works very well, but Snap it is kind of a pain in the butt because you don't know if your image is going to work until you've actually queried Amazon. I've tried in vain to use Snap it for keep track of books I want to buy and it's always easier to just scan the barcode.

The new Flow search is a total overhaul of the existing Snap it tool, and it works so well that I just want to scan everything I see in my life and add it to a list of things I might potentially purchase in the future. When you switch it on, Flow turns your iPhone's camera into one of those scanners you're used to seeing in the check out aisle of Target except that instead of sticking to barcodes it scans the real-world for objects that might look similar to products in Amazon's database. It works like magic, basically instantly registering not just books and DVDs, but also pita chips, laundry detergent, Triscuits, and other consumable household items in about a second. It's always on, so you can just walk down an aisle in a store scanning items.

According to Amazon's VP of shopping Sam Hall, the goal is to make everything Amazon sells searchable in this way, but for right now, Flow works best with things that are in packaging. (In my experience, it only works with things in packaging, and it works best with items that have bold, big typography.) Hall wouldn't reveal much about the underlying proprietary image recognition tech, but it's nothing especially new. If you know what the template image of an item looks like, it's very easy to use a camera to recognize other similar images. It's how cameras find the faces to focus on, how Facebook recognizes your friends , and how bots try to crack CAPTCHAs.

According to Amazon's Sam Hall, though, the purpose of Flow isn't so much to change people's retail experiences in stores as to try to make it easy to replenish items that you're always buying. So that when you're out of toothbrushes or garbage bags or toilet paper it's easy to scan it in the process of doing everything else. You know, more for buying new deodorant from the bedroom than turning local stores into nothing but unofficial Amazon showrooms. But there's no doubt you'll want to use it for both.

To turn back to my original experience in the bookstore, though, I'm surprised that neither Amazon nor IBM are playing up the bargain hunting potential of augmented reality shopping, Why would I buy a book in person for $18 when I can have it on my desk tomorrow for $11? I already price compare using my phone and Flow makes it easier. Amazon could be very quickly become a Costco substitute: When I scanned the Raisin Bran box that the company sent me to test out the new tool, Amazon correctly identified the 18.2 ounce package, but it quoted me a price of $8.94—for three boxes. That's way better than I'm going to do at any grocery in New York.

On this last note, I'd be remiss to not mention that this is only going to hurt local businesses. Amazon is a mammoth company that's often accused of stamping out Mom and Pop shops, and the company's reps were careful to dance around the technology's implications for local businesses like the bookstores we know and love on our lunch breaks but never buy anything from. But Amazon is in the business of selling you things, not keeping small companies open. If you find that distasteful—and many do!—the best thing you can do in response is to keep buying local.

The most likely scenario is a combination between bargain hunting and pure convenience uses for the technology. Am I gonna scan and price compare? You bet. But I'm also probably going to buy new razor blades when I realize I'm out. And just when I thought I couldn't use Amazon for more stuff. [iTunes]